MAPPING THE RIVER 
hoisted the British flag, which had hitherto flown over my 
tent. It was, I think, the first time the British flag had 
waved over that river. The canoe was baptized the 
Elfrida, after my sister’s name. 
It will be remembered that only four men remained 
with me. Not one of them had ever been in a canoe 
before, except to be ferried across a river, perhaps; not 
one had the slightest idea of navigation, and it followed, 
of course, that not one had ever used a paddle or steered 
a canoe. 
As the river had never been surveyed, it was my 
intention to make an accurate map of its entire course 
as far as its junction with the Tres Barras, several 
thousand kilometres away, from which point I imagined 
the river must be slightly better known. Therefore, as 
I should be busy all day long with the prismatic compass 
and watch, constantly taking notes of the direction of the 
stream and the distances covered (checked almost daily 
by astronomical observations), I should not be able to 
take an active part in the navigation. 
The canoe was undermanned. Imagine her length, 
forty-two feet, with only two men to paddle. A third man 
was stationed on her bow to punt when possible and be on 
the look-out for rocks; while Alcides, whom I had 
promoted to the rank of quartermaster, was in charge of 
the steering. I had taken the precaution to make a 
number of extra paddles. We carried a large quantity 
of fishing-lines with hooks of all sizes, and cartridges of 
dynamite. 
The river was most placid and beautiful, and the water 
wonderfully clear. Unlike rivers elsewhere, the Arinos 
did not show a branch or a twig floating on its waters, not 
a leaf on its mirror-like surface. That did not mean that 
branches of trees, sometimes even whole trees, did not 
fall into the river, but, as I have stated already, the 
specific gravity of woods in that part of Brazil was so 
3 
